That sucks,

Is it here in Los Angeles?

Prison or jail is not a good thing. However for what it is worth, the gov't (Sheriff/Correction/Police) are obligated to the safety of inmates. TS may be considered male but they have to be separated from the general pop. I hope she is well.

If you are her friend get an attorney and demand from corrections that she be separated from the general pop., her safety is at stake and they are responsible for her safety even under custody.

That's one of the reasons I haven't planned any US tours...

I know too many people who have been arrested in a country other than their own, and I've never heard a story that ends well. It's bad enough that the USA has such a draconian attitude towards law and order to begin with, but their attitude towards TS individuals makes the problem so much worse.

Also, I'm pretty heavily involved in the decriminalization movement up here, so I'm also kind of worried about targeted for that reason. One of my sex worker colleagues (not a trans woman, but a sex work activist) was detained at the border for three days because the USCBP was looking for her, and confronted her with screen shots from her website when she tried to enter the country. She hasn't been allowed back in the USA since.

I don't know the provider being discussed, but I do hope she's released ASAP, I can't imagine the horrors she's experiencing in a male jail. I hope they've put her in protective custody, but if they don't have room, they'll probably just throw her in with the general population... it gives me shivers just thinking about it.